Injections are performed not just to treat your symptoms and the underlying condition but in many occasions to help obtain the diagnosis. With up to 36 bones and over 30 joints in the foot and ankle, along with tendons, muscles and ligaments all in close proximity, ascertaining where your pain is originating from can sometimes pose quite a diagnostic challenge. Diagnostic injections are used in these occasions to help diagnose the cause of your pain. Where the diagnosis has been made and confirmed, an injection can be used for therapeutic purposes. This may in some cases cure the underlying problem or alleviate symptoms.
When local anaesthetic (Marcaine or Chirocaine 0.5%) is injected into a joint or soft tissue structure, it will numb the injected area for up to 18 hours. If the injected area is the cause of your pain then you will notice a temporary relief of your symptoms. If you do not notice any relief of your symptoms then another cause for your pain will need to be looked for.
Steroid (Depomedrone 40mg) is usually injected along with the local anaesthetic. The steroid is used to treat any inflammation (tendon – tenosynovitis, joints – synovitis/arthritis, bursa – bursitis). While the local anaesthetic predictably relieves pain for several hours, the effect of the steroid is less certain and the response varies from patient to patient. In some patients, particularly those with severe pathology (i.e. severe arthritis), the steroid may have no noticeable effect at all. It typically takes 24 – 48 hours, but sometimes days for the steroid to start working and the results can last for anywhere from days to months. Steroids work to reduce inflammation (heat, redness, swelling, & pain). As a result you should feel less pain, swelling, stiffness and warmth and be able to function a little easier after a steroid injection.
If your injection works for 6 months or greater it may be worth repeating especially if you wish to avoid surgery. Too many injections at short intervals, is not only inconvenient but also can cause local tissue damage, which can also complicate any surgery you may have at a later date.
Your surgeon Mr Malik will request one or both types of injection. Either an ultrasound guided or/and an x-ray guided injection in theatre under general anaesthetic.
Ultrasound guided injections are used when injecting in or around soft tissue structures for example –
Certain preparations and precautions are necessary for injections:
If you are taking tablets to thin your blood (anticoagulants), please be aware of the following:
The radiologist will use the ultrasound images to guide the needle into the correct position. The skin is marked and cleaned, and a small needle placed in the exact spot for the injection. The steroid is in a special solution, which prevents it circulating – there are, therefore, no generalised side effects.
Most procedures take about 15 minutes.
You may be asked to rest in the X-ray department for up to 30 minutes after your injection. You may experience increased pain after the injection. This is due to a “steroid flare”. 1 in 5 patients experience this. You can walk normally after the injection. You may continue with your normal lifestyle, however you should not do any vigorous exercise for 24 hours after the injection. If possible, it is best to rest the joint for 24-48 hours. Studies have shown this may improve the effect of the injection. Please comlpete the pain diary (Pain diary form PDF link) and return to your surgeon Mr Malik at the follow up appointment.
There is a very small risk of introducing infection with any injection. If you notice the injeciton site is red, hot or you feel unwell or feverish after the procedure, please consult your surgeon Mr Malik or your GP.
When corticosteroids are used, they may cause loss of skin pigment or thinning of the skin at the injection site. Corticosteroid can also cause weakening of a nearby ligament or tendon with the possibility of rupture. Having injections under image guidance with correct placement of the needle helps minimise this risk.
The medication may also temporarily increase blood sugar and disrupt the body’s own steroid hormone balance, particularly in patients with hormone disorders.
You may experience a little bruising at the site of injection, particularly if you are taking blood thinning medication.
Local anesthetic may cause flushing, hives, chest or abdominal discomfort, and nausea. Viscosupplements, substances that act like naturally occurring joint fluid, may cause joint pain, swelling and inflammation. Contrast agent may cause allergic reaction.
After a steroid & local anaesthetic injection most people tend to have at least 12 hours of immediate pain relief. This is down to the local anaesthetic component of the injection. The steroid can take several weeks to start working.
This is impossible to predict. In general one would hope that the injection works for several months.
How often can I have the injections repeated?
Generally we would not repeat the injections less than 6 monthly. Steroids in particular can weaken tissue and cause side effects.
If the injections are giving only a short term relief then it is probably not wise to continue with injections. As the condition deteriorates injections will tend to have less of an effect.
Injections work best when done for mild conditions.
You must have someone with you to drive you home after the injection. This is because the injection of local anaesthetic may invalidate your car insurance.
A short and very safe general anaesthetic is used when injecting the joints around the foot and ankle. The joints in the foot are very small and accurate placement of the needle can only be confirmed with intra-operative x-ray guidance. Injecting fluid into a small joint space can cause significant pain as the joint capsule distends. Having a short general anaesthetic allows for a pain free and pleasant procedure and as you will be completely still, it ensures accurate placement of the needle into the correct joint space.
A – Placement of fine needle in ankle joint B – Radio-opaque dye confirms needle is in the joint
Certain preparations and precautions are necessary for injections. As you are a having a short general anaesthetic you will require to be fasted prior to the procedure.
If you are allergic to anything, please tell the staff before the start of your procedure.
After being put under a light general anaesthetic, a needle is accurately placed into the joint using x-ray guidance and under aseptic technique (clean). A small amount of radio-opaque dye is used to confirm correct placement of the needle in the joint and a small amount of local anaesthetic, steroid or viscosupplement is then injected into the targeted joint(s).
Most procedures take about 5 minutes.
You will be taken to recovery where you will then be transferred to the ward. You may experience increased pain after the injection with no systemic features or local redness. This is due to a “steroid flare” and 1 in 5 patients experience this. You can walk normally after the injection. You may continue with your normal lifestyle, however you should not do any vigorous exercise for 24-48 hours after the injection. If possible, it is best to rest the joint for 24-48 hours. Studies have shown this may improve the effect of the injection. Please complete the pain diary (Post injection form PDF link) and return to your surgeon Mr Malik at the next follow up appointment.
Viscosupplement injections also do not offer immediate pain relief and it maybe several weeks again before any noticeable improvement.
You must have someone with you to drive you home after the injection. This is because the injection of local anaesthetic invalidates your car insurance, but also because you have had a short general anaesthetic.
Orthopaedic Outpatient Department
30 Devonshire Street, London, W1G 6PU
tel: +44 (0) 203 7956053
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